1. Field of the Invention
This invention relates to automated sewing machines and means for feeding cloth or other workpieces through them. Previous inventions have addressed the problems of stitching or seaming pieces of cloth together, e.g., railway sewing machines. Unlike railway-type machines, wherein the machine is moved with respect to a stationary workpiece, or vice versa, the present invention must co-operate with a conveyor belt upon which the workpiece is loaded. The conveyor must be stopped and started at intervals to allow loading of the workpieces onto the belt.
2. Brief Description of the Prior Art
Previous patents embrace only the general problem of stitching or seaming workpieces together. In the present day automated garment manufacturing facilities there is a need for apparatus which has the capability of continuously sewing a conveyor carried workpiece at a constant stitch rate, even though the conveyor is intermittently stopped to load new workpieces on the conveyor. Prior art, railway type sewing machines do not lend themselves to solving this problem. As examples, both Gamble et al., U.S. Pat. No. 2,836,133, and Gentry et al., U.S. Pat. No. 2,724,352, comprehend railway-type sewing machines. Cloth workpieces are merely set in stationary frames and the sewing machines are moved relative to the workpiece on a railway. In Gentry, a variable speed drive attachment for altering the speed of the sewing machine is claimed. This attachment must be controlled by, one assumes, a skilled operator.
Whitehead, U.S. Pat. No. 2,855,877, shows a sewing machine mounted upon one stage which is itself mounted on a second stage. By utilizing a common driving mechanism, a continuous stitching pattern can be accomplished. The stitch pattern is altered by movement of the stages relative to each other.
All such railway type machines are too cumbersome to load and are sensitive to shapes and styles of workpieces and types of material. None of these references solves the problem of providing an automated, continuous sewing apparatus which allows intermittent loading of workpieces.